Abstract: Objective: To explore the application value of combined detection of serological indicators and hemolysis tests in the diagnosis of ABO hemolytic disease of the newborn (ABO-HDN). Methods: A total of 109 children were collected, and divided into the ABO-HDN group and non-ABO-HDN group.hemolysis tests and total serum bilirubin (TSB) detection were conducted to analyze the characteristics of ABO-HDN onset.Meanwhile, the indicators changes such as blood routine, procalcitonin(PCT) and Creactive protein(CRP) were detected to analyze the inflammatory conditions in the children. Results: The differences of the levels of TSB, hemoglobin, white blood cell count, neutrophil, PCT and CRP were statistically significant between the ABO-HDN group and the non-ABO-HDN group(P < 0.05 to P < 0.01).The results of ROC curve showed that the AUCs of TSB and CRP were 0.733 and 0.661, respectively, and the diagnostic efficacy of TSB was the highest.hemolysis tests in different combinations showed that the number of positive cases in combination was the largest, while the TSB in combination 3 was higher than that in the other two combinations, and the reticulocytes were higher than that in combination 1(P < 0.05). Conclusions: The combination of hemolysis tests and serological index detection plays an important role in the diagnosis of ABO-HDN.